1. Field of the Invention
The present invention relates to a golf club head having a score line groove.
2. Description of the Related Art
A score line groove is formed on many golf club heads. The score line groove can contribute to an increase in a backspin rate.
Japanese Patent Application Laid-Open No. 9-253250 discloses a head having a small groove formed on a face surface. The small groove is formed by utilizing a cutting trace when the face surface is formed.
Japanese Patent Application Laid-Open No. 2002-153575 discloses a concave part formed on a face surface by micro fabrication. The depth of the concave part is 5 to 10 μm, and the width thereof is 5 to 20 μm.
Japanese Patent Application Laid-Open No. 2007-202633 discloses a head having a small groove formed on a face part. The small groove has an opening width and a depth smaller than those of a score line.
Japanese Patent Application Laid-Open No. 2008-132168 (US2008/0125242, US2009/0312116, US2010/0261545) discloses a head including a plurality of score line grooves and a plurality of narrow grooves. An angle between the narrow groove and the score line groove is set to 40 degrees or greater and 70 degrees or less, clockwise as viewed from the toe side of the score line groove.
Japanese Patent Application Laid-Open No. 2010-88678 (US2010/0087270) discloses a head including a plurality of narrow grooves extending from a toe side to a heel side.
Japanese Patent Application Laid-Open No. 2011-234748 (US2011/0269568) discloses a head having a narrow groove formed in parallel with adjacent score lines in each region between the score lines.
Japanese Patent Application Laid-Open No. 2011-234749 (US2011/0269567) discloses a head having a plurality of score lines, first narrow grooves, and second narrow grooves formed on a face surface. The first narrow grooves are parallel to the score lines. The second narrow grooves cross the score lines.